Ultrasonic algae control
Ultrasonic algae control is a commercial technology that has been claimed to control the blooming of cyanobacteria, algae, and biofouling in lakes, and reservoirs, by using pulsed ultrasound.[1][2] The duration of such treatment is supposed to take up to several months, depending on the water volume and algae species. Despite the experimental demonstration of certain bioeffects in small samples under controlled laboratory and sonication conditions, there is no scientific foundation for outdoors ultrasonic algae control.
Academic studies
It has been speculated that ultrasound produced at the resonance frequencies of cells or their membranes may cause them to rupture. The center frequencies of the ultrasound pulses used in academic studies lie between 20 kHz and 2.5 MHz.[3] The acoustic powers, pressures, and intensities applied vary from low, not affecting humans, [4][5] to high, unsafe for swimmers.[6]
According to research at the University of Hull, ultrasound-assisted gas release from blue-green algae cells may take place from nitrogen-containing cells, but only under very specific short-distance conditions, which are not representative for intended outdoors applications.[7] In addition, a study by Wageningen University on several algae species concluded that most claims on outdoors ultrasonic algae control are unsubstantiated.[8]
See also
References
- Utiger, Taryn (14 April 2015). "Soundwaves kill algae in reservoir". Stuff (company).
- "Literature Review of the Effects of Ultrasonic Waves on Cyanobacteria, Other Aquatic Organisms, and Water Quality" (PDF). Wisconsin DNR.Gov.
- Kotopoulis S, Schommartz A, Postema M (2008). "Safety radius for algae eradication at 200 kHz – 2.5 MHz". 2008 IEEE Ultrasonics Symposium (PDF). pp. 1706–1709. doi:10.1109/ULTSYM.2008.0417. ISBN 978-1-4244-2428-3. S2CID 21382938.
- Wu X, Mason TJ (June 2017). "Evaluation of Power Ultrasonic Effects on Algae Cells at a Small Pilot Scale". Water. 9 (7): 470. doi:10.3390/w9070470.
- Suslick JS, Didenko Y, Fang MM, Hyeon T, Kolbeck KJ, McNamara WB, Wong M (1999). "Acoustic cavitation and its chemical consequences" (PDF). Phil. Trans. R. Soc. Lond. A. 357 (1751): 335–353. Bibcode:1999RSPTA.357..335S. doi:10.1098/rsta.1999.0330. S2CID 12355231.
- Postema M, Schommartz A (2008). "Ultrasound and swimmer safety". Fortschritte der Akustik: DAGA 2008, 34. Deutsche Jahrestagung für Akustik, 10.-13. März 2008 in Dresden, Deutsche Gesellschaft für Akustik, Mar 2008, Dresden, Germany. Fortschritte der Akustik: 467–468.
- Kotopoulis S, Schommartz A, Postema M (2009). "Sonic cracking of blue-green algae". Applied Acoustics. 70 (10): 1306–1312. doi:10.1016/j.apacoust.2009.02.003. S2CID 110406431.
- Lürling M, Tolman Y (2014). "Beating the blues: Is there any music in fighting cyanobacteria with ultrasound?". Water Research. 66 (1): 361–373. Bibcode:2014WatRe..66..361L. doi:10.1016/j.watres.2014.08.043. PMID 25240117.